This invention relates to the art of rotary drum filters, and more particularly, to an improved means for stripping, or cleaning the filter media supported on the drum.
Rotary drum filters formed of a rotating cylindrical configuration have long been known, in which the surface of the drum is formed by screening supporting a porous filter medium through which dirt laden air or the like is passed, with the air passing through the filter medium from the exterior of the cylinder, with the undesired material to be removed from the air, filtered out on the exterior surface of the medium. With time, the medium becomes clogged, and the foreign matter must be stripped from the medium to permit continuance of filtration. To this end, one or more nozzles have in the past been arranged for movement over the surface of the medium as the drum is rotated, with the nozzles connected to a suction source, so as to strip or clean foreign matter from the medium.
These nozzles have in the past been connected to the suction source by means of a flexible tube, so that the nozzle can be moved back and forth with respect to the drum.
However, where particulate matter filtered out on the medium is of an abrasive nature, conventional materials, such as employed in the formation of flexible tubing are subject to abrasive deterioration under the action of the filtered material being removed. Further, the flexible tubing must be kept away from the filter surface to prevent damage thereof.